Norma McCorvey, who was 22, unwed, mired in addiction and poverty, and desperate for a way out of an unwanted pregnancy when she became Jane Roe, the pseudonymous plaintiff in the 1973 U.S. Supreme Court decision that established a constitutional right to an abortion, died Feb. 18 at an assisted-living facility in Katy, Tex. She was 69.

Her death was confirmed by Joshua Prager, a journalist working on a book about Roe v. Wade. The cause was a heart ailment.

Ms. McCorvey was a complicated protagonist in a legal case that became a touchstone in the culture wars, celebrated by champions as an affirmation of women’s freedom and denounced by opponents as the legalization of murder of the unborn.

When she filed suit in 1970, she was looking not for a sweeping ruling for all women from the highest court in the land, but rather, simply, the right to legally and safely end a pregnancy that she did not wish to carry forward. In her home state of Texas, as in most other states, abortion was prohibited except when the mother’s life was at stake.

On Jan. 22, 1973, the Supreme Court handed down its historic 7-to-2 ruling, written by Justice Harry A. Blackmun, articulating a constitutional right to privacy that included the choice to terminate a pregnancy.

The ruling established the trimester framework, designed to balance a woman’s right to control her body and a state’s compelling interest in protecting unborn life. Although later modified, it was a landmark of American jurisprudence and made Jane Roe a figure­head — championed or reviled — in the battle over reproductive rights that continued into the 21st century.

Ms. McCorvey fully shed her courtroom pseudonym in the 1980s, lending her name first to supporters of abortion rights and then, in a stunning reversal, to the cause’s fiercest critics as a born-again Christian. But even after two memoirs, she remained an enigma, as difficult to know as when she shielded her identity behind the name Jane Roe.

She admitted that she peddled misinformation about herself, lying about even the most crucial juncture in her life: For years, she claimed that the Roe pregnancy was the result of a rape. In 1987, she recanted, saying that she had become pregnant “through what I thought was love.” Although the details of her account were legally unimportant, abortion foes pointed to the lie to discredit Ms. McCorvey and her case.

According to the most sympathetic tellings of her story, she was a victim of abuse, financial hardship, drug and alcohol addiction, and personal frailty. For much of her life, she subsisted at the margins of society, making ends meet, according to various accounts, as a bartender, a maid, a roller-skating carhop and a house painter. She found a measure of stability with a lesbian partner, Connie Gonzalez, but even that relationship reportedly ended in bitterness after 35 years.

Harsher judgments presented Ms. McCorvey as a user who trolled for attention and cash. Abortion rights activists questioned her motives when she decamped in 1995, after years on their side, and was baptized in a swimming pool by the evangelical minister at the helm of the antiabortion group Operation Rescue.

The minister, Flip Benham, told Prager, who profiled Ms. McCorvey in Vanity Fair magazine in 2013, that he had come to see her as someone who “just fishes for money.”

By her own description, she was “a simple woman with a ninth-grade education.” She presented herself as the victim of her attorneys, Linda Coffee and Sarah Weddington, whom she accused of exploiting the predicament of her unwanted pregnancy to score a victory for the abortion rights cause.

Roe v. Wade, which became a class-action suit, was a watershed for women in general but irrelevant for Ms. McCorvey in particular. After an initial court victory for her, Texas mounted an appeal that dragged on long past Ms. McCorvey’s due date. By the time the Supreme Court announced its decision, her baby was 2½ years old. She had given the child up for adoption and learned of the ruling in a newspaper article.

Norma Nelson — her middle name was variously spelled Lea, Leah and Leigh — was born in Simmesport, La., on Sept. 22, 1947. Her father, a television repairman, was largely absent from her life.

She grew up in Texas, spending part of her adolescence in a Catholic boarding school and at a reform school for delinquents. Her mother told Prager that she beat her daughter in fits of rage over the “wild” behavior that included sexual promiscuity with men and women.

In her teens, Norma began a short-lived marriage to a sheet-metal worker, Elwood “Woody” McCorvey. Her mother raised their daughter, Melissa. Ms. McCorvey’s second baby, born out of wedlock, was adopted by another family.

She said she became pregnant with the Roe baby during a relationship in Dallas. An adoption lawyer referred her to Coffee who, like Weddington, was a recent law school graduate seeking a plaintiff to test the constitutionality of the Texas abortion law.

At the time, many well-to-do women seeking abortions traveled to states or countries where the procedure was legal or easily available, according to Leslie J. Reagan, a historian and the author of the volume “When Abortion Was a Crime: Women, Medicine, and Law in the United States, 1867-1973.”

Women like Ms. McCorvey, who did not have money to travel, had several undesirable options. They could entrust themselves to abortion providers who were not medical professionals or attempt to perform abortions on themselves — decisions that frequently resulted in infection or death — or they could obtain no abortion at all.

Ms. McCorvey was not the first plaintiff to challenge a state abortion law, but Roe v. Wade was the first such case to work its way through the appeals process to the Supreme Court. She used the pseudonym Jane Roe to protect her privacy. The defendant, Wade, was the Dallas County district attorney, Henry Wade, an official responsible for enforcing Texas abortion laws.

Years later, Ms. McCorvey expressed bitterness at what she described as her attorneys’ unwillingness to help her find what she needed — an abortion, even an illegal one.

“Sarah sat right across the table from me at Columbo’s pizza parlor, and I didn’t know until two years ago that she had had an abortion herself,” Ms. McCorvey told the New York Times in 1994. “When I told her then how desperately I needed one, she could have told me where to go for it. But she wouldn’t because she needed me to be pregnant for her case.”

“Sarah saw these cuts on my wrists, my swollen eyes from crying,” she continued, “the miserable person sitting across from her, and she knew she had a patsy. She knew I wouldn’t go outside of the realm of her and Linda. I was too scared. It was one of the most hideous times of my life.”

After the Supreme Court ruling, Ms. McCorvey did not live in total anonymity, as has been erroneously reported, but lived a mainly private existence before revealing herself in interviews and then in a memoir written with Andy Meisler, “I Am Roe” (1994). She worked in abortion clinics, “trying to please everyone and trying to be hardcore pro-choice,” she told Time magazine.

“That is a very heavy burden,” she said. Moreover, she said that her social background as a poor high school dropout made her ill at ease among the largely upper-class and well-educated activists who helped make abortion a matter of urgent national importance in the 1960s and 1970s.

“I wasn’t good enough for them,” she once said. “. . . I’m a street kid.”

Her conversion came about when Benham, the head of Operation Rescue, opened an office near one of Ms. McCorvey’s clinics and befriended her. She announced that she opposed abortion rights except in the first trimester — a position that put her in fundamental conflict with other antiabortion activists, who opposed abortion in all circumstances. Nevertheless, her defection was hailed as a victory for their cause.

Weddington looked suspiciously on Ms. McCorvey’s conversion and once described her former client as a person who “really craved and sought attention.” Ms. McCorvey attributed her philosophical reversal to her being “worried about salvation.”

She wrote another memoir, “Won By Love” (1997), with co-author Gary Thomas, founded the Dallas-based Roe No More ministry and reportedly became a Catholic. She participated in antiabortion protests and was arrested in 2009 for disrupting the Senate confirmation hearings on Sonia Sotomayor’s nomination to the Supreme Court.

Gloria Allred, the women’s rights lawyer who for a period represented Ms. McCorvey, told the Times in 1995 that Ms. McCorvey was justified in feeling abandoned by the women’s movement.

“She was shut out of many national pro-choice celebrations. She attended but for the most part she was not invited and it was a very hurtful experience,” Allred said. “When she did speak . . . she was really very eloquent, not well-educated but speaking from the heart, and I think she had a lot of common sense in what she was saying about choice.”

But neither did Ms. McCorvey find a comfortable home among conservatives in the antiabortion movement, many of whom regarded lesbianism as immoral.

“Neither side was ever willing to accept her for who she was,” the historian David J. Garrow, a Pulitzer Prize-winning biographer and the author of “Liberty and Sexuality: The Right to Privacy and the Making of Roe v. Wade,” said in an interview.

Ms. McCorvey supported herself in part through honoraria, book royalties and other income she generated from her role in the abortion debate. By 2013, according to Prager’s article in Vanity Fair, Ms. McCorvey was relying on “free room and board from strangers.”

Survivors include her daughter Melissa and two grandchildren. Nothing is publicly known of the two children Ms. McCorvey gave up for adoption, according to Prager.

“I don’t require that much in my life,” Ms. McCorvey told the Times in 1994. “. . . I just never had the privilege to go into an abortion clinic, lay down and have an abortion. That’s the only thing I never had.”